300 



REPORT — 1898. 



ampei-e, 4 volts, 3 hours. He also obtained excellent results with the 

 process of Vortmann and Foregger. Three grammes of pure caustic soda 

 are added to the neutral zinc solution. At a temperature of 50°, with a 

 current density of 0'5 to 1'5 amperes, the precij)itation of the zinc is com- 

 plete in one hour and a half. 



The Determination of Nickel and Cobalt. {Part I.) 

 By Hugh Marshall, D.Sc, F.R.S.E. 



Bibliography. 



• The references marked with an asterisk refer to both nickel and cobalt, the remainder to nickel only. 



Of the various methods of determining nickel and cobalt electrolyti- 

 cally, that employing the sulphates in presence of ammonium sulphate 

 and ammonia is by far the best known and most frequently employed. 

 Next to it Classen's oxalate method and Brand's pyrophosphate method 

 are probably those most frequently referred to. Of these three the former 

 is, primd facie, the preferable one, owing to the great simplicity of work- 

 ing it and the everyday character of the reagents employed, which are 

 readily obtainable in a pure condition. Unless other methods can be 

 shown to have a marked superiority in some important respect, we may 

 assume that it will continue to be the general method for ordinary work, 

 though the others might prove advantageous in special circumstances. 

 The greater part of the investigation so far has therefore been devoted 

 chiefly to a study of this method, and although only a limited number of 

 experiments have been carried out with the other methods, the results 



